Impression material



Patented Nov. 24, 1953 hdtddi'd "rear orrics IIVIPRESSION MATERIAL Bernardo E. Taylor, New York, N. Y., assignor to Max E. Michaelson and Jack Gold, both of New York, N. Y.

Serial N 0. 258,754

No Drawing. Application November .28, 1951,

6 Claims; (01. 2 -27) This invention relates to a material for use in making sets out-artificial teeth and more particularly to a material for making accurate impressions of a patients mouth so that sets of artificial teeth comfortable to the patient can be produced from the impressions. The invention also relates to a method of making the impression material.

Before a set of artificial teeth can be made for a dental patient, an impression must be taken of the patients mouth and especially of the tissue and bony structure in his mouth. The impression is usually made in the dentists ofiice and is then sent to a dental technician who proceeds to make a set of artificial teeth having substantially the same contour as the impression. In this way, the patient is supplied with an accurate substitution for his missing teeth and the missing tissue and bony structure in his mouth.

In order to obtain a desirable impression of a patients mouth, the material used should accurately follow the tissue and bony structures upon which the dentist is seeking to construct an artificial denture for supplying the missing parts. For example, the material should not bend, distort or compress the tissues while in the patients mouth, nor should it be displaced by mucous secretions. Furthermore, it should have properties for easy and quick preparation and should have substantially constant working properties even though it is simply prepared and even though atmospheric conditions such as temperature and humidity may vary considerably.

It should be leasant to the taste, non-irritating to the tissues of the mouth and easy to re move without distortion. It should be easily correctible by the addition of more material in case an inaccurate impression is made.

The impression materials now in use are not satisfactory for a number of reasons. Many of the materials require considerable preparation by the dentist without even oiiering an assurance that they will have substantially constant working properties for diiierent batches of material prepared. Variations in their working qualities are also pronounced with changes in atmospheric conditions such as temperature and humidity. Other materials include oils which smart or sting and mildly irritate the soft tissues of the mouth, as well as waxes which are manipulated only upon the application of an external force, this force in turn compressing and displacing the underlying tissues.

The materials are also displaced by mucous secretions and are not equally effective in taking impressions of the upper and lower jaws. Many of the materials are not easily correctible, so that an entirely new impression must be made in case the previous impression is at all inaccurate. Some of the materials set too quickly while in the mouth, thereby preventing the dentist from thoroughly mixing the material before it is inserted into the mouth and accurately manipulating the material after it is so inserted. Other materials quickly lose moisture after they are removed from the mouth and produce a shrinkage which results in an imperfect impression.

This invention provides a denture material which overcomes the above disadvantages and other disadvantages as well. The invention also includes a method of preparing such a material.

An object of this invention is to provide a denture material for making an accurate impression of a patients mouth.

Another object is to provide a denture material of the above character which can be easily and quickly prepared and which will have substantially constant working properties after every preparation, even with changes in atmospheric conditions. I

A furtherobject is to provide a denture material of the above character which produces no irritation of the tissues in the mouth and which has a pleasant taste while in the mouth.

Still another object is to provide a denture material of the above character which can be easily manipulated in the mouth to obtain an accurate impression and which can be easily removed from the mouth without in any way impairing the impression.

A still further object is to provide a denture material of the above character which retains its shape after removal from the mouth, even upon the application of moderate shearing and chipping forces.

Another object is to provide i -ethods of making a denture materiai having the above properties.

Other objects and advantages will be apparent from a detailed description of the invention and from the appended claims.

In one embodiment of the invention, the following chemicals used in the wei ht percentages shown:

The paracoumarone-indene resin is combined from polymers of couznarone and indene. Coumarcne and indene have the following chemical formulae:

where R is an aliphatic radical. The polymers of coumarone and indene may be attached to one another through the oxygen atom of the con marone molecule and/ or through the double bond in the 5-atom ring of the indene molecule.

The triethylene glycol ester of hydrogenated rosin has the following chemical formula as its base:

H H H 11 H H 0 ea. tattattathat 1; 1'1 E l 1': EI 1'1 0 l C\ l CHa CH3 CH 04H CH3 CHa CH3 CHa where the undesignated carbon molecules in the 3 cyclohexane and cyclohexene rings are saturated by hydrogen atoms.

The glycerol ester of hydrogenated rosin has the following chemical formula as its base:

where the undesignated carbon molecules in the cyclohexane and cycloheXene rings are saturated by hydrogen atoms.

The glycerol and glycol esters are used as the predominant chemicals in the impression mate rial because of their high resistance to oxidation and coloration when exposed to atmospheric temperatures and to such elevated temperatures as are required to prepare the impression material. At the elevated temperatures, the esters also have plasticizing qualities which cause the impression material to be easily manipulated.

The paracumarone-indene resin is included in the impression material to impart a sharp melting point to the material. Thus, the material remains soft While it is in the patients mouth since it has been previously heated above its melting; temperature, but it hardens quickly aiter the introduction of water into the mouth because of the quick hardening action provided by the resin at its temperature of solidification. The resin also imparts an. increased hardness to the material below its temperature of solidification and improves the appearance of the material by giving it a gloss.

The aniline dye imparts color to the impression material so that the impression mat 12.1 can be distinguished from the base to which it added to form a replica of the patients gum structure. The color provided by the aniline dye also enhances the appearance of the impression material. The calcium carbonate is added to impart body to the impression material and to increase the opacity or the material.

To prepare the impression material, the paracumarone-indene resin is first heated to a tem perature slightly below 120 C. for a period of time sufficient to convert the resin completely into a viscous liquid. The glycerol of hydrogenated rosin is then added slowly to the liquefied resin and is stirred in the resin during and after the addition until a thorough blend of the chemicals is obtained.

When the resin and the glycerol ester have been thoroughly mixed, the triethylene glycol ester of hydrogenated rosin is added slowly with constant stirring while the temperature of the mixture is maintained at approximately C2, and the stirring is continued until a homogeneous mixture is produced. While the mixture is maintained at a temperature of approximately 100 C. the aniline dye is next added in powdered fOl'l'fl and the calcium carbonate finally added in powdered form. The mixture is constantly stirred during the above additions to obtain a thorough blend. The resultant impression material is in the form of a paste at the elevated temperature and in this form is poured into suitable containers for disbursement to dentists.

Before the impression material disclosed above can be used, a rough impression of a patients mouth must first be prepared from stone or other suitable material. This rough impression somewhat smaller than the final impression will be, since it serves only as a base for the addition of the impression material. A surface of Wax or other suitable material is then added to the stone to prepare the rough impression for the addition of the material disclosed above.

A container of impression material is next heated to a sufiicient temperature to convert it into a liquid having a heavy consistency, and the material is applied by brush to the rough impression. The impression material may jell somewhat as it is applied but will soften again when the impression is inserted into the patients mouth.

Upon insertion of the impression in his mouth. the patient proceeds with a series of prescribed movements, such biting, whistling, yawning and sucking. These movements cause the impression material disclosed above to adapt itself to the contour of the patients mouth to very close tolerances. The impression material is then chilled by pouring a steady stream of cold Water into the patients mouth and after being chills The impression material disclosed above has several important advantages. It is prepared easily and quickly and even with such ease in preparation, it has substantially constant and desirable working properties for different batches of material prepared. Such uniformity in Work ing properties is obtained even with changes in atmospheric conditions such as temperature and humidity. Because of its uniformity in working properties, dentists are able to judge accurately the time which they can use for preparing an accurate impression before the material sets.

Upon insertion of the rough impression into the mouth, the impression material disclosed above adapts itself upon relatively slight pres sure from the tissues, such as in smiling, puckering and swallowing, to conform to the contour of the mouth. Since no undue force is necessary to alter the position of the impression material, it does not distort or compress the tissues in the mouth.

It creates impressions with smooth and even surfaces since it is not affected by mucous secretions in the mouth, and it is effective in creating accurate impressions for both upper and lower sets of teeth. It does not react in any way with the moisture or other chemicals in the mouth to produce a dehydrating action which causes adhesiveness and which prevents the material from being easily removed from the mouth. Furthermore, the material is not irritating to the mouth tissues in any way and it is pleasant to the taste.

One of the most important advantages possessed by the impression material is its adaptability in being added to material which has previously been applied. This adaptability is especially advantageous where the dentist has made a somewhat incorrect impression on a previous attempt and desires to rectify the inaccuracies in the impression by the addition of more impression material. The impression material is also advantageous in that it dries quickly, but not too quickly, after removal from the mouth. As a result, the impression does not become distorted by the loss of water during the hardening period.

It should be realized that other chemicals can probably be substituted for the chemicals disclosed above. For example, other compounds can probably be used as fillers in addition to calcium carbonate and many compounds can be used as the dye. Furthermore, some variations in the percentages by Weight of the difierent materials can probably be made from the percentages disclosed above without materially afiecting the desirable properties of the impression material. It should also be realized that the impression material disclosed above can probably be used for other purposes than making dentures.

Although this invention has been disclosed and illustrated with reference to particular applications, the principles involved are susceptible of numerous other applications which will be apparent to persons skilled in the art. The invention is, therefore, to be limited only as indicated by the scope of the appended claims.

What is claimed is:

1. An impression material, including, glycerol ester of hydrogenated rosin comprising approximately 48 to 60 parts by weight, triethylene glycol ester of hydrogenated rosin comprising approximately 24 to 36 parts by weight, paracumaroneindene resincomprising approximately 10 parts by weight, a dye for providing a distinctive color to the material and having a relatively small percentage by weight, and a filler for providing body to the material and having a relatively small percentage by weight.

2. An impression material, including, glycerol ester of hydrogenated rosin comprising approximately i8 parts by weight, triethylene glycol ester of hydrogenated rosin comprising approximately 36 parts by weight, paracumarone-indene resin comprising approximately 10 parts by weight, calcium carbonate comprising approximately 6 parts by weight, and a dye comprising less than 1 part by weight.

3. A method of forming an impression material, including, heating approximately 10 parts by weight of paracumarone-indene resin to a temperature slightly below 120 C. to convert the resin into a viscous fluid, adding approximately 48 to 60 parts by weight of a glycerol ester of hydrogenated rosin to the resin at the elevated temperature to obtain a first blended mixture, adding approximately 24 to 36 parts by weight of a triethylene glycol ester of hydrogenated rosin to the mixture at a temperature of approximately C. to obtain a second blended mixture, and adding a relatively small percentage by weight of a suitable filler material at an elevated temperature.

4. A method of forming an impression material, including, heating approximately 10 parts by weight of paracumarone-indene resin to a temperature slightly below C. to convert the resin into a viscous fluid, adding approximately 48 parts by weight of 2. glycerol ester of hydrogenated rosin to the rosin at the elevated temper-ature to obtain a first blended mixture, adding approximately 36 parts by weight of a triethylene glycol ester of hydrogenated rosin to the mixture at a temperature of approximately 100 C. to obtain a second blended mixture, adding approximately 6 parts by Weight of calcium carbonate at a temperature of approximately 106 C. to obtain a resultant blended mixture, and adding less than 1 part by weight of a dye to provide a pleasing color to the resultant blended mixture.

5. An impression material, including, glycerol ester of hydrogenated rosin comprising approximately 48 to 60 parts by weight to provide plasticizing properties to the material at elevated temperatures and to resist oxidation at atmospheric temperatures, triethylene glycol ester of hydrogenated rosin comprising approximately 24 to 36 parts by weight to provide plasticizing properties to the material at elevated temperatures and to resist oxidation at atmospheric temperatures, and paracumarone-indene resin comprising approximately 10 parts by weight to provide a sharp melting point to the material at a temperature above atmospheric temperatures.

6. An impression material, including, glycerol ester of hydrogenated rosin comprising approximately 48 to 60 parts by weight to provide plasticizing properties to the material at elevated temperatures and to resist oxidation at atmospheric temperatures, triethylene glycol ester of hydrogenated rosin comprising approximately 24 to 36 parts by weight to provide plasticizing properties to the material at elevated temperatures and to resist oxidation at atmospheric temperatures, paracumarone-indene resin comprising approximately 10 parts by weight to provide a sharp melt- 2,860,670 7 8 ing point to the material at a temperature above OTHER REFERENCES atmospheric temperatures, a filler for providing Neville Resins and plasticizers," February 5, body to the material and comprising approxi- 1945, page matell" 6 parts by g and a compnsmg Cumar (Barrett Div., Allied Chem. and Dye less than 1 part by Welght 5 CorpJ, page 16, November 12, 1948.

BERNARDO TAILOR Hercules Ethyl Cellulose Resin Plasticizers References Cited in the file of this patent ggggg i ggg e g fi 11 1952 UNITED STATES PATENTS pages 13 19, Number Name Date 10 2,362,934 Schlaanstine Nov. 14, 1944 

1. AN IMPRESSION MATERIAL, INCLUDING, GLYCEROL ESTER OF HYDROGENATED ROSIN COMPRISING APPROXIMATELY 48 TO 60 PARTS BY WEIGHT, TRIETHYLENE GLYCOL ESTER OF HYDROGENATED ROSIN COMPRISING APPROXIMATELY 24 TO 36 PARTS BY WEIGHT, PARACUMARONEINDENE RESIN COMPRISING APPROXIMATELY 10 PARTS BY WEIGHT, A DYE FOR PROVIDING A DISTINCTIVE COLOR TO THE MATERIAL AND HAVING A RELATIVELY SMALL PERCENTAGE BY WEIGHT, AND A FILLER FOR PROVIDING BODY TO THE MATERIAL AND HAVING A RELATIVELY SMALL PERCENTAGE BY WEIGHT. 